Tamper



July 8, 1969 J. G. BERKHOUDT ET 3, 4

TAMPER Filed Nov. 28, 1967 Sheet of s I INVENTORS.

AT NEKS y 8, 1969 J. 5. BERKHOUDT ET AL TAMPER Sheet 2 of 3 Filed Nov. 28, 1967 INVENTORS.

JOHN G. BERKHOUDT JOHN M. MELISZ @444 @aa/n ATTORNEYS,

y 3, 1969 J. G. BERKHOUDT ET AL 3,453,940

I TAMPER Filed Nov. 28, 1967 Sheet 3 of s INVENTORS JOHN G. BERKHOUDT JOHN M- MELISZ AT TORNEYS United States Patent US. Cl. 94-48 6 Claims ABSTRACT OF THE DISCLOSURE An engine-driven vibratory compactor of the type comprising a manually directed machine for compacting or tamping earth, sand, gravel, concrete, asphalt, or other materials, such as in foundation or paving fill operations or the like; featuring an improved vibration-isolated combination maneuvering control handle and fuel tank arrangement. This arrangement comprises a vertically stand ing rigid box-sectioned column which is cantilever-springfixed at its lower end to the machine frame and carries at its upper end a resiliently supported hand grip device extending generally horizontally therefrom at an adjustable angle so as to be disposed at an elevation conveniently in reach of the hands of the operator; the hollow interior of said column providing a fuel carrying space, whereby the machine engine fuel is carried within a vibration-isolated storage cell and the operator is shielded from the machine vibration forces in improved manner.

Background and objects of the invention Whereas conventionally constructed industrial tampers of the vibratory compacting type sometimes employ flexible handle-bar type steering devices with a view to insulating the operators grip from the vibrating mechanism, the present invention provides an improved vibration-isolation system. Vibrations inducing fore-and-aft motions of the handle structure are absorbed at the base of the handle support column or post, and vibrations inducing vertical motions of the handle are absorbed at the upper end of the support post. Furthermore, the above mentioned object is attained through use of a hollow but substantially rigid column member extending vertically from the machine base to support the operators hand grip device; the hollow interior of the column member functioning simultaneously as a reservoir for the machine engine fuel.

The drawing By way of example, an embodiment of the invention is illustrated in the accompanying drawing wherein:

FIG. 1 is a side view illustration of a tamper of the invention, in operation;

FIG. 2 is an enlarged scale fragmentary top plan view thereof;

FIG. 3 is an enlarged scale fragmentary side elevational view thereof, partly in section;

FIG. 4 is a further enlarged scale fragmentary plan view of the fuel tank and control handle mounting arrangement; and

FIG. 5 is a fragmentary sectional view taken as suggested by line VV of FIG. 4.

Detailed description As shown in the drawing herewith, the invention may be embodied in an earth or concrete tamper, or the like, of the type comprising generally a chassis mounting an engine 12 of the eccentric fly wheel type, whereby operation of the engine imparts to the machine chassis a radial vibratory action. At its bottom end the chassis mounts a work shoe 14 for bearing against the ma- 3,453,940 Patented July 8, 1969 terial being worked. The chassis 10 is provided with a rearwardly extending bracket 16 mounting a transverse axle 18 upon which wheels 2020 are carried at opposite sides of the machine.

In the case of the present invention the operator hand grip and control support device is provided in the form of a relatively rigid but hollow column or post member as indicated generally at25; said post member being mounted by means of a spring plate 26 at its lower end to the bracket 16 as by means of machine screws 27. The post 25 is conveniently fabricated of square tube metal stock or by welding together four fiat metal plates, to provide the rigid box-sectioned construction as shown in the drawing herewith, but it may of course be fabricated in any other preferred manner. In any case the post member 25 is stoppered at its bottom end, as by means of a bottom plate 28 (FIG. 3) and is closed at its top end by a plate 29, thereby providing in the hollow interior of the post member an ample fuel storage space for the engine 12. A fuel filling opening and cover cap therefor is provided as indicated at 30, and a fuel antisplash tube such as shown at 31 is preferably provided as shown in FIG. 5.

The tank-post structure 25 is welded to the upper portion of the spring plate 26, and thereby rigidizes the upper end thereof. To attain any preferred resonance characteristic of the lower end portion of the spring plate 26, a fillet brace plate as shown at 32 may be welded or otherwise fixed in place below the tank-post 25 as best shown in FIG. 3. An engine fuel outlet connection into the bottom end of the tank structure 25 is readily provided as indicated at 34, and is illustrated to support a fuel cleaner bowl 36 from which fuel flows through a flexible conduit 38 into the engine carburetor 40- (FIG. 3). A grappling bracket as shown at 41 is also conveniently welded to the upper end of the spring plate 26 so as to extend therefrom for grappling connections with hoist lift hooks or the like, for convenience in transporting the machine from place to place. Handles as shown at 42--42 may also be fixed to extend laterally from the upper end of the column 25 to facilitate manual maneuvering of the machine on the wheels 20--20 from one work site to another.

The operator hand grip and maneuvering control device of the mechanism comprises a handle carried by a bearing box 44 which is welded or otherwise fixed to the rear face of the upper end of the post-tank 25 to accommodate in pivotably mounted relation thereon the operator control handle 45, as by means of a journaled bolt 46. The arms of the handle 45 terminate in cylindrically shaped bushing portions 47--47 (FIG. 4) which journal in suitably apertured side wall portions of the box 44. At their inner faces the bushings 4747 frictionally engage opposite sides of a pivot plate 48 which is carried by the bolt 46; whereby, when the bolt 46 is tightened, the handle 45 is effectively keyed to the pivot plate 48. A pair of elastic shock absorber blocks 5050 (FIG. 5) made of rubber or the like are mounted within the box 44 at positions above and below the pivot plate 48, and are held in position by a retainer or pressure plate 52 which is supported by screws .54 so as to be positionally adjustable within the box 44. Hence, the device may be adjusted so as to impose upon the pivot plate 48 any preferred degree of elastic restraint to oscillations relative to the tank-post 25. Upon lossening of the bolt 46, the handle may be angularly adjusted relative to the plate 48 and then retightened, whereupon the latter Will resiliently hold the handle 45 to extend substantially horizontally and rearwardly from the bearing block and at any preferred attitude such as to dispose the handle bar 45 into convenient reach of the machine operator as illustrated at FIG. 1, while at the same time permitting 3 the machine to vibrate vertically relative to the hands of the operator.

Thus, it will be appreciated that the machine of the invention features an arrangement wherein the combination fuel tank and control support post is isolated from machine vibration forces acting in fore-and-aft or horizontal directions, While the control handle 45 is resiliently isolated from vibration forces acting in vertical directions. Hence, the operators hands and arms are shielded from the vibration forces which are developed by operation of the machine engine; and these forces are thus unrestrained by the operators grip on the handle 45, whereby the machine may perform a most efiicient tamping job. Furthermore, it will be noted that because the control support post structure functions also as a fuel supply container for the machine engine; this arrangement eliminates need for a separate conventional type fuel tank. Such tanks are typically mounted on the engine or on the machine base; and therefore are subjected to inordinate vibration forces, to the detriment of the tank structure and to the fuel line connections to the engine.

Whereas only one form of the invention has been illustrated and described in detail hereinabove, it will be understood that various changes may be made therein without departing from the spirit of the invention or the scope of the following claims.

We claim:

1. In a vibratory tamper of the type including essentially a base mounting a liquid-fueled piston engine and an off-balance flywheel inducing radially directed vibrations to the working material, the improvement comprising:

a substantially rigid hollow column member; a flat cantilever spring plate interconnecting the lower end of said column member and said base such that said column member extends vertically therefrom, said spring plate being flexible only in a fore-and-aft horizontal direction with respect to said base thereby tending to isolate said column member from said tamper vibration acting in said fore-and-aft horizontal direction;

an operator hand grip handle member; resilient means carried adjacent the upper end of said column for supporting said handle to extend substantially horizontally from the upper end of said column member,

said column member being stoppered and provided with a liquid inlet and a liquid outlet connection device and arranged to constitute the fuel supply reservoir for said engine,

whereby said column member functions both as a support for said handle member and as a fuel tank for said engine, and whereby said handle is isolated from said tamper vibrations by said cantilever spring plate and said resilient means.

2. A vibratory tamper as set forth in claim 1 wherein said flat spring plate is partially gusseted to provide a predetermined preferred spring resonance characteristic.

3. A vibratory tamper as set forth in claim 1 wherein said column member includes four flat plates edge joined to form a rigid box-sectional column construction and upper and lower end plates, said liquid inlet being in said upper end plate, and said spring plate being Weld ailixed to one of said column flat plates which extends laterally of said tamper.

4. A vibratory tamper as set forth in claim 1 wherein said resilient means includes a bearing box affixed adjacent the upper end of said column member, a substantially horizontally disposed pivot plate disposed within said box, means extending exteriorly of said box to afiix said handle to said pivot plate, and a pair of elastic shock absorber blocks mounted in said box in engagement with opposed relatively upper and lower surfaces of said pivot plate, said shock absorber blocks serving to position said pivot plate within said box and resiliently isolate said handle from said column member and thus said tamper vibrations acting in vertical directions.

5. A vibratory tamper as set forth in claim 4 wherein a pressure plate is positioned within said box in engagement with one of said shock absorber blocks and adpustment means are provided to move said pressure plate within said box so as to adjustably compress said shock absorber blocks and thus impose upon said pivot plate a preferred degree of elastic restraint.

6. A tamper as set forth in claim 4 wherein said handle member is angularly adjustable relative to said pivot plate about a substantially horizontal axis extending laterally of said tamper.

References Cited UNITED STATES PATENTS 2,894,435 7/1959 Brown 9448 3,068,765 12/ 1962 Caufield 94-50 3,199,424 8/ 1965 Glass 9448 3,232,188 2/1966 Frohnauer 94-48 3,308,728 3/1967 Brown 94-48 3,336,848 8/1967 Moir 94-48 3,386,353 6/1968 Wells 9448 JACOB L. NACKENOFF, Primary Examiner. 

